<template>
  <view>
    <!-- 使用自定义检索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧的滑动区域 -->
      <scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh +'px'}">

        <block v-for="(item,index) in cateList" :key="index">
          <view :class="['left-scroll-view-item',index===active? 'active':'']" @click="activeHandler(index)">
            {{item.cat_name}}
          </view>
        </block>
      </scroll-view>

      <!-- 右侧的滑动区域 -->
      <scroll-view ref="scrollView" scroll-y="true" :style="{height:wh +'px'}" :scroll-top="scrolltTop">
        <view class="cate-lv2" v-for="(lv2,index2) in cateLevel2" :key="index2">
          <view class="cate-lv2-title">/ {{lv2.cat_name}} /</view>
          <!-- 二级分了下的三级分类列表 -->
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(lv3,index3) in lv2.children" :key="index3" @click="gotoGoodsList(lv3)">
              <image :src="lv3.cat_icon"></image>
              <text>{{lv3.cat_name}}</text>
            </view>
          </view>
        </view> 

      </scroll-view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        // 当前设备可用的高度
        wh: 0,
        active: 0, // 激活项的索引值

        scrolltTop: 0,
        // 分类数据列表
        cateList: [],
        // 二级分类
        cateLevel2: []
      };
    },
    onLoad() {
      const systemInfo = uni.getSystemInfoSync()
      this.wh = systemInfo.windowHeight - 50
      this.getCateList();
    },


    methods: {
      // 获取分类列表的数据
      async getCateList() {
        const {
          data: res
        } = await uni.$http.get("/api/public/v1/categories")
        if (res.meta.status != 200) return uni.$showMsg()
        this.cateList = res.message // 设置一级分类
        this.cateLevel2 = res.message[0].children
      },

      // 分类点击事件
      activeHandler(index) {
        // 出来选中的activie
        this.active = index
        // 重新伟二级分类赋值
        this.cateLevel2 = this.cateList[index].children
        // TODO 没有生效 
        this.scrollTop = this.scrolltTop === 0 ? -1 : 0
      },

      // 跳转到商品列表界面
      gotoGoodsList(item) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
        })
      },
      gotoSearch(){
        uni.navigateTo({
          url:"/subpkg/search/search"
        })
      }
    }
  }
</script>

<style lang="scss">
  .scroll-view-container {
    display: flex;
    background-color: white;

    .left-scroll-view {
      width: 120px;

      .left-scroll-view-item {
        height: 60px;
        background-color: #F7F7F7;
        text-align: center;
        line-height: 60px;
        font-size: 12px;
      }

      .active {
        background-color: white;
        position: relative;

        &::before {
          // 创建伪元素
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #C00000;
          position: absolute;
          top: 50%; // 距离顶部50%
          left: 0;
          transform: translateY(-50%); //  向上回退50%
        }
      }

    }

    .cate-lv2-title {
      font-size: 12px;
      font-weight: bold;
      text-align: center;
      padding: 15px 0px;
    }

    .cate-lv3-list {
      display: flex;
      flex-wrap: wrap;

      .cate-lv3-item {
        width: 33.33%;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        margin-bottom: 10px;

        image {
          width: 60px;
          height: 60px;
        }

        text {
          font-size: 12px;
        }
      }
    }
  }
</style>